Devices to actuate alarms such as lights are well known in the art but generally alarm systems relate to means for actuating warning lights or audible alarm systems upon the occurrence of a detected intrusion. The difficulty with the use of prior art devices such as alarms, for example lights is that they are generally actuated in response to stimuli which are not intended for actuation of the devices for example, barking dogs or ringing telephone bells.
Other systems include infra-red detectors for use as intrusion detectors but such systems alone do not detect the characteristics surrounding intrusion such as breaking glass or the infrasonic pressure wave generated by an opening door.
While it is known to utilize infrasonic detectors for example as shown in U.S. Pat. Nos. 3,914,755, 3,573,817, 3,940,069 and 4,134,109 no prior art arrangements are known to utilize infrasonic detectors to actuate lights, or other devices for selected time periods either to signal unauthorized intrusion or to allow time for the light to be on by entry to provide light to, for example, reach a light switch.